


Filthy Billow

by Skillet_Writer



Category: SpongeBob SquarePants (Cartoon)
Genre: Bodily Fluids, Bodily Functions, Embarrassment, Gen, Humiliation, Masturbation, Mating Cycles/In Heat, Mating Season, Sperm, going into heat
Language: English
Status: Completed
Published: 2020-08-06
Updated: 2020-08-06
Packaged: 2021-03-06 08:02:08
Rating: Mature
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 3,041
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/25750069
Author URL: https://archiveofourown.org/users/Skillet_Writer/pseuds/Skillet_Writer
Summary: SpongeBob wakes up chock full of... SPERM?! Each year for a week he experiences the agonizing and humiliating effects of mating season on his body. It seems no matter what he tries, he can't escape the torment. But there's one way out he's had yet to try...
Comments: 3
Kudos: 11





	Filthy Billow

**Author's Note:**

> Originally posted on Fanfiction.net: https://www.fanfiction.net/s/13660617/1/Filthy-Billow
> 
> Hello, friends! I had this one lying around unfinished for the past 3 months and I'm excited to finally bring it to you. This is only chapter 1. The real story has yet to begin. Warning: this story is going to be pretty lewd. But if you know me, you know that's kind of my realm. Heh.

**Filthy Billow - Chapter 1**

* * *

SpongeBob awoke one morning to a tingly sensation. He rubbed his eyes of sleep and began to sit up, groaning when he could feel the sensation travel to the tips of each of his four limbs. Little spasms like sparks went off in his fingers and toes, and all throughout his body he felt a light tremble.

Immediately, he knew what was up. He'd been dreading this feeling all year, knew it was inevitable, but still found himself unprepared for the occasion. _It's normal,_ SpongeBob had tried to convince himself since it first showed up late puberty. _It's totally normal to have icky sperm shoot from your pores for a week each year._

And it _was_ normal. In sponges, at least. While most poriferans were limited to asexual reproduction, some possessed the ability to reproduce sexually also. A male-identifying sponge can produce sperm within its body that is sometimes released through the _oscula_ , which is essentially a sponge's anal canal. Or urinary tract. They went both #1 and #2 through it; details really ain't all that important.

Upon fully sitting up and swinging his feet to dangle over the side of the bed, SpongeBob could feel a trickle of something wet between his legs. He bit his bottom lip in a grimace, his buck teeth leaving a clear indent in the pink flesh. "Barnacles, why so _soon_?" he whined before getting up and waddling to the bathroom like a penguin.

"Meow."

"Go away, Gary. It's nothing," came SpongeBob's muffled voice from behind the closed door. His face was buried in his shaky palms, flushed a bright red, even though his snail was the only one around to witness his turmoil, and Gary had seen him go through this many times before. It was just the whole idea of this happening to his body _at all_ that made SpongeBob blush in shame. _Neptune, I hate this. Yuck._

His legs kicked about to ward off the feeling of them falling asleep, as his square cheeks were firmly planted on the toilet seat and had been for a good five minutes now. A squeak escaped his lips when a thick, wet mass was finally forced from his nether aperture, hitting the water with a splash. Reluctantly, he peeked into the bowl, almost unsure of whether or not he released sperm and not _another_ bodily excrement, to his own embarrassment. "Eww," he whispered down at the thing. Indeed it was sperm, and a gnarly glob of it.

The first release was always the most contained; a clot that had developed over a considerable period of time in preparation for mating season and had collected in his inners. The first _may_ have exited through his most private hole (and at least that made for easy clean-up), but the rest to follow would be expelled through practically every other orifice in his body, mouth and nose included. And SpongeBob had a _lot_ of orifices. Lucky him.

As SpongeBob got up from the toilet, a shudder went through his entire body that for a second made him see stars. He blinked away the blackness, dizzy, and leaned on the sink for support. There was a knot in his stomach, and then something like a firework, and it caused him to double over, his hands clutched around his sides.

"How am I supposed to get ready for work like this?" he said with a groan. It was Monday. Oh, _why_ did it have to be Monday? He was expected to get to work on time, like any normal work day, but with how things were already going for him, he could tell that the week was not going to be a typically pleasant one.

Having been through this many times before, SpongeBob knew of how he could combat his natural functions. All male sponges went through this godawful bullshrimp eventually, so there were commonly known methods to lighten the burden of spewing literal _cum_ for a seemingly endless seven days.

Well, for starters, he could plug up his pores. Each one of those little craters in his body served as an opening for sperm to leave, and although walking around looking like a dirty cheesegrater wasn't SpongeBob's idea of style, it would serve to prevent the milky stuff from gushing out of him at random. It'd happened more than once in his life, and needless to say, it was absolutely embarrassing.

" _Here's your order, sir!"_

" _Why, thank you."_

" _...Oh, shrimp-"_

_At the comment, the fish looked up to meet his server's frantic eyes. He raised an eyebrow, concerned at the sponge's display._

_SpongeBob was looking hot to the touch and his blush had him tinted orange all over. He stood unmoving, seemingly spaced out, but in reality, was caught in a pleasure-induced stupor. For a few seconds, he went completely stiff, stiffer than a board, before all of a sudden—_

" _Gah!" he gasped, convulsing. His body had suddenly loosened up, but despite that, he felt unable to walk away. His pores began to expand and contract rapidly, and following a strangled moan, sperm blasted out from him at all angles, a white cloud forming around him._

_Many of the customers recognized the substance immediately._

" _Eww!"_

" _Gross!"_

" _I'm outta here!"_

" _No, wait!" SpongeBob called. "Don't go!" Then he curled up in shame, made to feel even worse when Mr. Krabs found him and berated him for driving out all the hungry customers._

So, yeah, plugging his pores seemed like a worthwhile option.

But there was a downside. If SpongeBob _were_ to occlude his openings, the sperm would still need to leave his body somehow, lest he drown from the inside out. (Which admittedly wasn't _technically_ possible because, one, it would find a way out -the sperm _always_ finds a way out- and two, drowning? They're fucking under water!) Let's rephrase this, shall we? _Hypothetically_ , with no openings to escape through, his organs could be flooded by waves of jizz and something might collapse or he might choke to death. Though realistically, he'd probably just experience some severe diarrhea. That oscula would not be very happy, and neither would SpongeBob.

So let's go over some other choices. Well… there was the risky _bathroom_ option. Just thinking about it made SpongeBob feel dirty. He'd done it before: perform his job at an insane speed and when business slowed down a bit or during a designated break time, hightail his ass to the men's room and rub one out ASAP.

Sponges, uh, they don't possess penises like some creatures do. (He could sprout a phallic appendage if he wanted to, but it would feel no different than an arm or a leg.) They don't possess vaginas either, though one could argue his pores are practically just that. In order to get off, SpongeBob would play with his sensitive pores, or if that didn't work, he might finger his oscula. Except that felt _super_ dirty, so he often abstained from it.

Reaching orgasm as soon as possible was top priority in a situation where his job and his reputation were on the line. Sometimes he felt a wave of unwanted pleasure coming on due to a buildup of sperm, and he'd have to force the orgasm to pass in the privacy of a stall so he didn't release back in the kitchen. He'd often pump an entire first into a pore, unintentionally stretching it out and leaving it gaping and looking freshly de-virginized in the process. Then he'd go stiff and then loose and then fill the bathroom with a filthy billow.

Other times he'd have to actually leave the building. If the orgasms got to be too much, the dumpster served as a place where he could temporarily let out his moans (and of course, his _cum_ ). The sensation of his pores opening and closing was a perfect mix of pleasure and pain he refused to admit to himself that he liked. A cloud of sperm was not the only thing that hung over his head after orgasm; there was always a cloud of guilt.

Once, Squidward caught him in the act. He'd been in the bathroom for quite some time, longer than he would've liked, and Mr. Krabs -after hearing commotion from hungry customers- sent the octopus out to go and search for him.

" _SpongeBob! SpongeBob?" Squidward called out, blatantly unconcerned. Hey, if SpongeBob was lost forever, it'd be a dream come true. "SpongeBob," he repeated. "Tch, I don't get paid enough for this."_

_He swung the door open and stepped into the men's room, glancing around briefly. He'd only just turned to leave when a sound caught his ear._ A moan.

_Squidward suddenly looked alert as ever. "Was that…? No. Nope. I'm outta here."_

" _T-tartar sauce."_

" _Is someone…" There was no mistaking it. Someone was in there and was "...jerking off?" The octopus shook his head, facepalming. Disgusting, absolutely disgusting. Who the Davy had the nerve to- Wait. "Oh, no. Oh please goodness no." It was another moan that made Squidward's face drain of color. He had to hear that voice nearly 24/7, there was no way in hell that that moan_ didn't _belong to his coworker, who should be doing his fucking job and not getting his rocks off in the dirty, unhygienic bathroom stall and-_

" _SpongeBob, are you_ kidding _me?!"_

_From the inside of the stall on the far end of the room, SpongeBob squealed. He removed wet fingers from his tight oscula, and in doing so, accidentally (only made an accident because someone else was now in the room) threw himself over the edge._

" _Holy kelp," he breathed. Welp, there went his dignity. A white mist poured out from the stall, and he could hear Squidward almost gag upon noticing it. He pulled his pants back up, trembling, and braced himself for the utter humiliation. His eyes were wet with fresh tears that Squidward could not see._

_The door rattled. "SpongeBob, open up! I seriously cannot believe you. Out of all the immature things you've done, this has_ got _to be the worst! Just wait'll ol' man Krabs hears about this. What is he gonna think when he learns that his greatest employee was busy spanking the seamonkey during his shift? Honestly, SpongeBob," he said, sounding genuinely disappointed, "I would never have expected this behavior from you." In other words,_ you're too pure for that.

Ha. SpongeBob _wished_ he were too pure for that. But unfortunately, one struggles to maintain purity when faced with the notion that they're gonna be horny and expelling their bodily fluids into the water that everybody breathes for a whole damn week. _Inevitably._ Like, there was no way to change that. Or… was there?

Okay, so maybe, just _maybe_ , there was one _other_ method SpongeBob could use. But it fucking sucked. Like, really bad. Like _Plankton-just-stole-the-formula_ kinda bad, only even _that_ seemed like a more pleasant scenario.

A sex change.

Now, SpongeBob really had nothing against the idea of switching genders. Plenty of fishfolk did it. He had a couple customers come by that had a beard one day and breasts the next (and vice versa). SpongeBob was all about catering to the customer's needs, and just being a courteous person in general, so he didn't even raise an eyebrow when met with a person who identified uniquely. But as for SpongeBob himself, it just… wasn't something he had any desire to do.

Sure, the sponge was no stranger to crossdressing. He could rock a pair of heels and some coral blue number two semigloss lipstick, and overall sport a girly look quite nicely, if he did say so himself. He was pretty ambiguous when it came to a lot of things, actually. But altering his body just for the sake of _one week_ was an unpleasant thought.

You see, sponges are hermaphrodites, meaning they have the ability to alternate between sexes without the means of surgery; SpongeBob could swap out his sperm for eggs if he wanted to. Sure, it'd be a painful night of intricately fooling with his genitals, but at least he wouldn't be cumming anymore, right?

(Not that he _didn't_ want to bust a nut during his lifetime. He wasn't much of a prude, and he didn't like to live his whole life in No Nut November, either. Cumming was nice, just... not like _this_.)

Anyways, here's the catch -and there's always a catch: SpongeBob's self-sex change would not only alter his inners, but his appearance as well. The once flat-chested SpongeBob would sprout a pair of tiny boobs (pretty functionless, but if you'll recall Girly Teen Girl), hardly B cups. He might even denote to more feminine facial features, but considering his eyelashes and full lips, one would hardly be able to tell the difference. The thing SpongeBob dreaded most was the ability to get _pregnant_. At least as a male, he didn't have to worry about some unknown guy's DNA traveling through the currents and into his body uninvited and fertilizing him. Yeah, _hell no._

It was recommend that a sponge not change their sex more than once a year, for legal purposes, and for health concerns. There were some less-than-desirable side effects to re-modifying one's genetics shortly after they've already been modified. It fucks with the hormone balance, and gametes, and some other technical stuff that, in the simplest of descriptors, would _not_ be cute. To sum it all up, this meant that SpongeBob would have to live as woman for an entire year, lest he suffer some detrimental consequences.

It pretty much goes without saying that SpongeBob did not want his natural spongey functions to rule _that_ much of his life, even if for only a year. Because mating season happened _every year._ Knowing that, he might as well make the full transition. Might as well just be Sponge _Barb_ or Spong _ette_ or some other humiliating title. It just wasn't something he wanted to do.

His birth certificate said he was born "male", and while he wasn't half the man he wished he was (and could never be), he'd seize any ounce of manliness he could get. People already saw him as docile and feminine (not that those things in of themselves were _bad_ things, per se, but it still didn't help his self-esteem), let's not make it worse. Self-expression was great and SpongeBob loved to push society's boundaries of normal, but he wasn't sure living as the other gender was something he could manage.

"Who knows?" he mused, examining his face in the mirror. "I mean, if worse comes to worst…" He placed the back of his hand to his cheek and was almost surprised at how hot it felt. He couldn't really be when his face was so painfully red. He needed to cool off and get ready for work.

The shower ran, and SpongeBob stepped into the tub, already completely naked. He shrieked. "Barnacles!" The water was _freezing_. He wanted it cold, but not this cold! It caused an intense shiver to go through him, and that's all it took to start off his week of misery. That's all it took for his body to shake like a jackhammer before projecting jets of jizz from a couple of his holes, maybe three.

Even after repeatedly scrubbing each of his holes for a whole (pun intended) ten minutes, he still felt hot and full. There was a light pressure in various places beneath his spongy flesh, present when sperm traveled out from his center. It just sat there, waiting to be ejaculated and making SpongeBob feel absolutely disgusting.

When people say an animal is going into _heat_ , it's more than just a figure of speech. For SpongeBob, the poor boy would toil sweaty and overheated most of the day, with his raised anxiety levels only making things worse. His pores had a lot of functions, one being acting as a cooling system for him, but since they were so obstructed, he could hardly sweat; his body generated heat that was hard to get rid of. Somewhere in his insides there was a constant pulsating and pumping to produce sperm for mating season, which is what generated the heat, thus making even the coolest of rooms feel stuffy to him. Often he'd have to run to the bathroom during a work shift and repeatedly splash his face with water, lest he pass out.

Oh, yeah. Speaking of water… SpongeBob turned the knob and stepped out of the shower, reaching for a towel. He tied it around his waist and ran back to his bedroom as fast as his wobbly legs could carry him. "Please bear with me, Gare-Bear," the sponge said, rummaging through his drawers for some briefs. "I can already tell today's gonna be rough."

Oh, yeah. It would be.

He selected a pair and then placed his feet through the leg holes, carefully sliding the white garment on. He winced as the fabric slid across his waist. During mating season, his holes were especially sensitive, and having to dress caused him mild discomfort. And pleasure. Mild pleasure. Too much more contact and it would be enough to stir up his insides, and SpongeBob did _not_ want to ignite his loins at the moment.

But he had to put some pants on, too. He just had to. If it were legal and not so mortifying, he'd work in the nude, but uh, it was illegal and totally mortifying. After digging through his closet for a pair of pants (even if all of them were literally the same design), he put them on and then stood in front of his mirror.

"Do I look like a mess, Gary?"

"Meow."

"Gee, thanks." He rolled his eyes. It was a rhetorical question, anyway. As usual, his outfit was sharp, but he was looking ever so dull, worn down. One look at the sponge and you could tell he was not feeling himself. His eyes were a little red from stress, but nowhere near as red as his cheeks. The lip beneath his wavering smile quivered. His shoulders slumped at his sides. There was a lack of bounce in his step as he left the room and headed downstairs for breakfast.

**Author's Note:**

> Let's hope I can get past my ADHD and finish this one. Sigh...


End file.
